Just a small snippet from a token-saving discussion on the Discord last night.

If you need to iterate over neighboring tiles (for example when writing a path finding algorithm for 7DRL), this natural approach is pretty token heavy:

-- four directions, 29 tokens
for direction in all{{-1,0},{0,-1},{1,0},{0,1}} do
local x,y=direction[1],direction[2]
end
-- eight directions, 45 tokens
for direction in all{{-1,0},{0,-1},{1,0},{0,1},{1,1},{-1,-1},{1,-1},{-1,1}} do
local x,y=direction[1],direction[2]
end
-- eight directions, 43 tokens
directions={0,-1,-1,0,1,0,0,1,1,-1,-1,1,1,1,-1,-1}
for i=1,16,2 do
local x,y=directions[i],directions[i+1]
end
-- eight directions, 30 tokens
directions={-1,0,1}
for x in all(directions) do
for y in all(directions) do
if x!=0 or y!=0 then
--
end
end
end

Why not use trigonometry?

-- four directions, 16 tokens
for i=0,1,0.25 do
local x,y=cos(i),sin(i)
end
-- eight directions, 24 tokens
for i=0.125,1,0.125 do
local x,y=flr(cos(i)+.5),flr(sin(i)+.5)
end

-- eight directions, 23 tokens
directions=explodeval("0,-1,-1,0,1,0,0,1,1,-1,-1,1,1,1,-1,-1")
for i=1,16,2 do
local x,y=directions[i],directions[i+1]
end

Provided, of course, you have this defined (which you absolutely should, because it's universally useful):

function explode(s)
local retval,lastpos={},1
for i=1,#s do
if sub(s,i,i)=="," then
add(retval,sub(s, lastpos, i-1))
i+=1
lastpos=i
end
end
add(retval,sub(s,lastpos,#s))
return retval
end
function explodeval(_arr)
return toval(explode(_arr))
end